Electric plant.



0. SCHALLER.

ELECTRIC PLANT.

APPLIOATIOH FILED AUG. 7, 1907.

Patented Apr. 15, 1913.

2 SHEETS-SHEET 2.

0/10 Adzal/er ilk/nay UNITED sures PATENT OFFICE.-

OTTO SGHALLEB, O! STEGLFTZ, NEAR BERLIN, GERMANY.

ELECTRIC 21.1mm.

T 0 all whom it may concern.

Be it known that I, O'rro ScHALLEa, a citizen ofthe German Empire, and residing at Steglitz, near Berlin, Germany, have invented new. and useful Improvements in Electric Plants, of which the following is a full, clear, and exact description.

Insystems of electric car lighting wherein the car axle is used to,drive the dynamo furnishing the current for the lighting system, the speed of the car axle of necessity varies considerably because of 'ariations in the speed of the car or train,and therefore the terminal voltage of the-dynamo ,will vary within wide limits. p

The object of the present invention is to obtain an approximately constant potential at the terminals of the working circuit irrespective of great variations in speed of the mechanically driven power shaft. To this end there is provided a second shaft and electrical means, consisting of one or more auxiliarydynamos, for driving such second shaft, whereby the sum of the speeds of the main and auxiliary dynamos, or the relative speed pf parts of the main dynamo rotating one in 'oiiposition to the other, and therefore Specification of Letters latent. Xifiawama filed August 7, 1901. man No. 387,631.

PatentedApr.15,1913.

the set shown in Fig. 1 into double generators.

Referring to the drawings and first to Fig 1, there is indicated a Shaft-W which may be driven in either direction or first in one direction, as would happen if the shaft be considered as driven from acar axle by a belt R or' in any other manner. shaft-W are mounted the armature A of a dynamo D and the armature a of ya dynamo-electric machine M, the fields" of which are externally excited as .shownin Figs. 2 to 1;

A secontfiset is provided comprising a motor M an a dynamo Df ha'ving' their re- -spev tive arnlatures A and a mechanicallycorinected by a shaft W, and this second Set is electrically driven.

The set DM operates as a direct current converter, and the set D M as a; motorbooster.

gather in series and toe battery B which latter is preferably a storage battery. The

in series, and to a working circuit, in. which the voltage of the working circuit will re-* are included transla ng devives su h 11 main approximately constant.

The inv ntion will be best understood from a consideration of the following detailed description with reference to the ac c'oinpanying drawipgs forming a part of this specification, with the understanding that the showing of the drawings is largely indicative and that the invention is susceptible of many changes and modifications without material departure from the principles of the invention.

Referring to the drawings Figure 1 is a diagram illustrating asimple embodimentof the invention; Fig. 2 is a diagram similar to that oi -Fig. 1, but showing the field connections; Fig. 3 is a diagram showing an elaboration of thesystem of Fig. 1; Fig. ids a diagram showing an embodiment of the-in; 5

vention in a double direct current generator and a dynam'otor; Fig. 5 is a diagram showing a special type obtained by combining parts of Fig. 1 into a machine having the induced and inducing parts oppositely rota table; Fig. dis a diagram showing; another embodiment of theinvention. Figs. 7, 8 -and 9 are diagrams illustrating special types obtained by combining some parts of F, f, f are :shown as fed by the .bat'itery B.

variable speed shaft/W and the freely run- ,ning electrically driven shaft W is substantially constant.

{dynamo-electric machine Mma-y be e.

If 6 be the voltage of the battery .13, the .fmotor M" will have e* be' volts and its. Espeecl at the excitation to which .it'sfield f" is adjusted may assume the value n .co'riresponding. to the counter 'electromotive force e.

Considering the booster D so dimensioned ;that at a speed n with thefieldFlait fill supply a ,voltage of B, then s wa l-11 .1 $1.151 the -vo1tage8 i direction and then after atime in the other.

O th

The arma-tures a and a are connected toarmatures A and A are connected together;

shown in Fig. 1, may be'excited by the batterv B, as in Fig. 2, where the field coils The connections are such'that of the speeds of the mechanically driven If the speed of the shaft W increases to :n', then dynamo'D may generate a voltage E' and the voltage at the terminals of the.

Cri

the speed of the shaft W would he 2 and the electromotiveforce of the booster would be so that again the speeds n+n :n, and the Voltages lld-E :l*l without having-altered the fields at. all. I

Should the shaft \V stop the set M I)" will still run, and the arinatures A and a will consume only the small voltage. corresponding to their resistances. It, however. the shaft W is running in thereverse. direc tion, then the shaft will incl-casein speed to such an extent that Tr m/:11, hut it thi he t'fltl('. ll{ll)l(, loriner conditions may he estahlishml loy reversing, the current in the armatures or fields in the well known manner. v v

In the foregoing, the fields l F", f and f are assumed to he excited constantly without regulation, but it obvious that special regulations oispeed may he hrought ahoul hy utilizing the varying voltages at the hrushes ol' the ditl'erent' maehines for reinf rcing or weakening the magnetic lields.

vd'ith variahle load the exci ation may he altered hy additional or suhtraetiomil main or shuntwindings to either or hoth sets of fields j, l and In F g. 3 subtractronal series vindlngs f, and f are provided for the rnw'rhines M M and additional series windings I and l'.. for the.

machines l), D I

Other means for influencing or regulating the speed are obvious to those skilled in the art and require n'ospecial illustration or description.

The z-irinatures A, and a of the main set and A, a of the auxiliary set of rotating electrical u'iachinery may be arranged in a common field, thus forming a douhle direct current generator M, l), and a dyuai'uotor M, D as shown in the diagram of Fig. "l.

A saving of space may be attained it, in-

V stead of employing the booster D", the main dynamol'l), Fig. 5, is so arrangedthat its held Fand its armature A may both he re volved either in the same or the opposite sense, the former by means of the auxiliary dynamo M and the shaftlV', the latter by the motor M and the shaft It is evident that the. reverse arrangement. is possible, in which case W would drive the arma ture and the tield. In Fig. 5 slip rings are necessary to feed exciting current. to the rotating field F. 7

It is also considered unnecessary to illustrate or describe at length known means of regulal'in", such as counter main current windings, through which the main current from B passes into (I, a-. (Fig. weakening the fields ff and thus inlluencii'ig the regulation, while the main worl ing current from compounds through F,, F... \Vith the aidol' these known arrangen'ients; the voltage of the working circuit, Torinstance with a varjahle load, may increase, remain constant, or (h #reas'e.-' 'lliisds especially the ease h alterin;, the voltage I) of the auxiliary current .s'Ut-l ltt', which latteris illustrated here-as a hallery. i

H it is desired to still further compress lhe arrangement shown in Fig/5, the armalul'es a, and u innylau-oinhined'toforma. single armature. which together withthe allnatiire may hel arrangeddll a-singlc' lield l The l in arinal ure windings may then he wound on the same armature iron. They are shown in .l'ig o as a ring winding (1 and a drum windin; the former hein; con Ilti'teil lo the left, the latter to the right hand connnutator'. 'lhe hrushes b, of theqoo lel't hand commutator are led [manila-M1, ter) ll. those In. of the right. hand commuta- (or are connected to the load lrin tl'ie\\ 'ay' illustrated hy the l'oriner figures. 'l'he's'in- ,lle lield l is excited from the hatlery B through slip rings N, and is coupled (hykeys or the like) to the shalt WV, driven hy hclt and oulley ll. The a liiltltlll'tfi r/ and form one solid hod and may he hodily rotated together with their windings and eounnuhe 11a tors through a hollow shaft in the 'heal-' lugs l)... lt will he readily uuderslmul that shall may he. turned within thc"hearings ll, lneeln'iiiically, and shall within the h arings l7 electrically, as'shown in Fig. 8 or vice, versa. Also other lll(('lltlfllttll u'ieans f may he employed for driving, for instance, a car axle, if the. plant is to he used in 0on neetion with a carriage, for instance for lighting a train. described will he nroducedin this case. The arrangement of Fig. (3 is in fact only a further development of the arrangement of Fig. 8. Thus two rotary arinatures (Land A will be on a common shaft V and two rotary fields or one common 'ficld F *on asecond shaft \V. Again, one of the. two N shafts, in Fig. (3 the field shaft WV, is driven by means of a pulley R from a mechanical source of power. One armature ais com All the effects previously12 0 

